Hadith 1:452

Narrated 'Aisha:

On the day of Al-Khandaq (battle of the Trench' the medial arm vein of
Sa'd bin Mu'ad was injured and the Prophet pitched a tent in the
mosque to look after him. There was another tent for Banu Ghaffar in
the mosque and the blood started flowing from Sa'd's tent to the tent
of Bani Ghaffar. They shouted, "O occupants of the tent! What is
coming from you to us?" They found that Sa'd' wound was bleeding
profusely and Sa'd died in his tent.